Internal combustion engine with controlled lubrication supply

ABSTRACT

A coordinated set of controls for a throttle and lubricating pump with a fail-safe feature. In normal operation, the lubricating pump output is a function of the speed setting of the throttle whereby at maximum speed setting the output of the pump is set at its maximum by interconnected linkages. In the event of a failure of the linkages, the lubricating pump is set at its maximum output for all throttle settings.

United States Patent [1 3,648,677

Stranbel [45] an M, 11972 [54] INTERNAL COMBUSTION ENGINE [56]References Cited WITH CONTROLLED LUBRICATION UNITED STATES 1P ATENTS@UPPLY 1,630,217 5/1927 [72] Inventor: Max Straubel, Mumch, Germany1,929,010 10/1933 3 302 752 2/1967 3 A Z d 1 [7 sslgnee un app WerkeGmbH Mumch Germany 3,435,914 4/1969 [22] Filed: Aug. 29, 11969 PrimaryExaminer-Manuel A. Antonakas [21] 854166 Attorney-Wilson8zFraser [30]Foreign Application Priority Data ABSTRACT Nov. 27, 1968 Germany ..P1811 128.9 A coordinated set of controls for a "Home and lubricating pumpwith a fail-safe feature. In normal operation, the lubricating pumpoutput is a function of the speed setting of [52] 11.8. C1. ..123/196 S,184/64, 184/628 the throttle whereby at maximum Speed setting the outputof [51] Int. Cl ..Fl6n 29/02 the pump is Set at its maximum byinterconnected linkages In [58] Field ofSearch ...l84/6 C,6D,6Y, 27 R,29;

the event of a failure of the linkages, the lubricating pump is set atits maximum output for all throttle settings.

9 Claims, 8 Drawing Figures Patented March 14, 1972 3,648,677

4 Sheets-Sheet 1 INVENTOR MAX STRAUBEL BY Mdww m ATTORNEYS PatentedMarch 14, 1972 4 Sheets-Sheet F3 INVENTOR MAX STRAUBEL BY 4.) Mum,

ATTQRNEYS Patented March 14, 1972 4 Sheets-Sheet 5 I NVENTOR MAXSTRAUBEL BY Jim ATTORNEYS Patented March 14, 1972 3,648,677

4 Sheets-Sheet 4 INVEIITOR MAX STRAUBEL ATTORNEYS INTERNAL COMBUSTIONENGINE WITH CONTROLLED LUBRICATION SUPPLY BACKGROUND OF THE INVENTIONThis invention relates to internal combustion engines having lubricatingoil pumps and more particularly to such engines where the pump output isa direct function of the power setting of the engine control.

DESCRIPTION OF THE PRIOR ART Lubricating pumps for internal combustionengines have been driven from the crankshaft of the engine. Therefor thepump output is increased with the speed of the crankshaft. It has beenknown to provide a further degree of variation of lubricating pumpoutput by adjustment of the pump. Pump adjusting means can be coupled tothe engine control as to the carburetor so that the quantity oflubricant supplied by the pump for a given number of revolutions of thecrankshaft is altered as the engine control setting is altered. Forexample, the quantity of lubricating oil issued from the pump can beincreased for a given number of revolutions of the crankshaft as thespeed or power setting for the engine is increased, and conversely thepump output is decreased with reduced speed or power settings. One sucharrangement is to bias both the throttle and pump adjusting means to anoload setting, i.e. low pump output and low throttle setting, as bymeans of a biasing spring and to adjust the settings against the springforce through a linkage including a flexible cable, such as a Bowdencable, up to the highest settings.

Destructive conditions can occur with the above arrangement where thecontrol linkage breaks or becomes disconnected such that the throttle ismaintained in an advanced setting and the lubricating pump is retractedby the biasing means to its no-load or minimum output setting. If thefailure of the linkage is not observed and corrected in a short time,the deficiency in the oil supply to the engine destroys it or seriouslyimpairs its operation. Further, in normal operation, a gradual extensionof the control cable to the lubricating pump will gradually bring abouta reduction in the pump setting for a given throttle setting, therebylowering the supply of lubricating oil. While this reduction is minor atthe outset it can become significant to a degree which impairs operationof the engine.

SUMMARY OF THE INVENTION This invention avoids the above disadvantagesby control linkages and biasing means for the throttle of an internalcombustion engine and the lubricating pump therefor which are arrangedto bias the pump to the maximum output setting and are linked to acommon operating device so that when fully operative the throttle andpump adjusting means are coordinated as a direct function. In thisarrangement, the engine is supplied with sufficient oil even if thecontrol train to the lubricating pump malfunctions since the pump isbiased to a setting and any failure tends toward a setting for thegreatest supply of lubricant.

A feature of the invention involves the use of two Bowden cables from asingle operating device to control the throttle and lubricating pumpsettings.

Another feature is the control operating device comprising a two armedlever having cable couplings for the pump and throttle control cableswhere a cable is connected to each arm.

Another feature is a control operating device comprising a slidereciprocating within a guide attached to the paired Bowden cables.

Another feature is a rotating handle or handwheel type control for thepaired Bowden cables.

Another feature resides in the biasing means for the throttle orcarburetor and the lubricating pump in the form of a compression,tension or flexure spring oriented toward minimum setting for thethrottle and toward maximum setting for the pump.

A further feature is the construction of the lubricating pump to providean adjustable stroke by cam adjustment of the piston of the pump througha disc coupled to a rotatable sleeve enclosing a portion of the piston.The head of the sleeve is formed into a cable pulley and is axiallydisplaceable by a camming action to move the disc and thus the pistonposition along the axis of its cylinder. The cam can be in the form of ahelical slot in the sleeve into which a pin extends so that as thesleeve is rotated, the fixed pin riding in the slot causes adisplacement of the sleeve along its axis. The sleeve can be biased toone extreme of its range of axial travel by a helical torsion springcoaxially surrounding the sleeve, secured at one end to the sleeve andat the other end to the fixed housing of the pump whereby the springbias tends to maintain the pump adjusted for maximum stroke.

An object of the invention is to improve internal combustion engines.

Another object is to avoid unsafe operating conditions for internalcombustion engines, particularly such conditions arising frominsufficient lubrication.

Another object is to coordinate throttle settings with a variablelubrication pump setting in a simple and expeditious manner.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of thelubricating pump, carburetor and throttle, biasing means therefor, levertype, control operating device and control linkages for an internalcombustion engine;

FIG. 2 is a schematic diagram as FIGi. ll showing a cable actuated slidetype, control operating device;

FIG. 3 is an internal combustion engine, in which a carburetor serves asa power control, with a lubricating oil pump and its operating deviceshown diagrammatically;

FIG. 4 is a section taken along line A-B of the operating device of FIG.3;

FIG. 5 is a side elevation of a lubricating oil pump having an adjustingdevice with portions broken away and sectioned to reveal its internaldetails;

FIG. 6 is a top view of the lubricating oil pump as shown in FIG. 5;

FIG. 7 is a front elevation of the upper portion of the pump of FIGS. 5and 6 showing a part of the stroke adjusting means; and

FIG. 8 is a side elevation with portions broken away and sectioned of acarburetor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An output control element 2,which can be a carburetor, and a lubricating oil pump 3 can be connectedto an internal combustion engine ll through conduits 4 and 5. Controldevices, for example the lever arms 6 and 7 are provided for control asa throttle for carburetor 2 and as a stroke adjusting means for pump 3.Carburetor control lever 6 is biased toward its one limit by tensionspring 8 and toward its opposite limit by Bowden cable 9 connected tothe two armed lever 10.

The tension spring 8 of carburetor 2 is biased toward the no loadsetting of the engine 1 and can be opposed and overcome by Bowden cable9 as displaced by lever 10. Oil pump 3 has its lever 7 biased to themaximum output setting by tension spring 11 and is adjusted by means ofBowden cable 12 and lever 10 to overcome the spring bias and at theposition for no load setting of carburetor 2, the pump lever 7 is setfor the no load setting or the minimum output per revolution of theengine crankshaft. For movement of control operating device lever 13 inthe direction of arrow 15 in FIG. I, clockwise, lever 6 for thecarburetor 2 is moved counterclockwise toward the full load position.Simultaneously, the lubricating oil pump 3 is adjusted to the maximumoil output per engine crank shaft revolution by relieving the tension inspring 11 to permit lever 7 to move counter clockwise. Movement of leverarm 13 in the direction of arrow 16, counter clockwise, sets thecarburetor control arm 6 to a reduced load position by the action ofspring 8, while lever arm 14 imposes tension on cable 12 and spring 11to move control arm 7 of the lubricating pump clockwise to a reducedoutput. Therefore, in the event of a failure, as the breaking of cable12, the engine will not suffer from lack of oil, since the lubricatingoil pump 3 is set automatically and immediately to the maximum outputper engine drive shaft revolution setting.

In FIG. 2 and subsequent drawings like reference characters refer tocorresponding elements of previously discussed figures.

FIG. 2 is similar to FIG. 1 in the construction and arrangement of thelubricating oil supply control means and the dependence of its settingon the setting of the carburetor of an internal combustion engine.Instead of the two armed lever 10 of FIG. 1, the operating device ofFIG. 2 is a slider 18 which reciprocates in guide or rail 17. A tensionspring 19 biases the slider to the no load setting for the carburetor 2and pump 3 and can be opposed by tension imposed by Bowden cable 20attached, for example, to a rotatable handle 21. The Bowden cables 9 and12 are attached to the opposed ends of slider 18 so that it impartsidentical but opposing motion to the cables 9 and 12 with the sameeffect as two armed lever 10 discussed with respect to FIG. 1. Movementof slider 18 is actuated by cable 20 as force is imposed or relieved toovercome or relieve the tension spring 19.

The internal combustion engine of FIGS. 3 and 4 has controls for thelubricating oil pump 3 and the carburetor 2 connected to rotatablehandle or grip 22 so that Bowden cables 9 and 12 move in opposite senseto each other as the handle is rotated. As best seen in the sectionedview of handle 22 in FIG. 4, rotation of handle 22 causes rotation ofthe internal sleeve section supporting cable connectors 24 and 25 sothat cables 9 and 12 are reciprocated with respect to guide sleeves 26and have their ends carried over an arcuate path within fixed housing23.

The lubricating oil pump 3 and its adjusting device are shown in detailin FIGS. 5 to 7. A piston 29 reciprocates in a housing 30 to positivelydisplace lubricant in cylinder 50 in a predetermined quantity accordingto the length of the piston stroke. A supply duct 41 and a dischargeduct 42 each extend to parts in the cylinder aligned with the body ofpiston 29. The piston body has a passage on its outer face extendingparallel to its axis and of restricted circumferential extent wherebythe passage selectively provides communication from the ports of ducts41 and 42 to the open region of cylinder 50 below piston 29. The piston29 is reciprocated and rotated simultaneously in the cylinder so thatthe enlargement of the region of cylinder 50 below the piston occurswhile passage 43 registers with supply duct 41 and reduction of thatregion occurs while passage 43 registers with discharge duct 42.

A worm 44 driven by the crankshaft of the engine which is to belubricated is journaled for rotation in pump housing 30 and engages acup-shaped worm gear 45. The worm gear 45 is secured to piston 29 sothat the piston is rotated therewith and can move axially thereof. Aspline coupling (not shown) can be employed for this purpose.

A lift cam 46 is secured to piston 29. Cam 46 is shaped on its undersidewith a rising face and a falling face to cooperate with a stud 48 orother cam follower member fixedly mounted on pump housing 30. The cam isangularly oriented with respect to passage 43 in piston 29 to impartrising and falling motion thereto coordinated with the porting of supplyduct 41 and discharge duct 42 to the open cylinder chamber. Acompression spring 49 is coaxially mounted on piston 29 and biasedbetween cam 46 and the interior of the cup of worm gear 45 to force thecam against stud 48.

In operation piston 29 is turned around its longitudinal axis by thecrankshaft of the engine by means of worm 44 and worm gear 45. Passage43 is in this manner alternately registered with intake duct 41 anddischarge duct 42. As the piston is rotated, it is reciprocated alongits axis through action of lifting cam 46 against spring 49 and stud 48.The orientation of elements is such that the piston is lifted when itregisters with the supply duct 41 (see the broken line representation)and is lowered when it faces discharge duct 42 (as shown in full lines).In this manner, the cylinder chamber 50 below piston 29 is filled whenthe passage 43 is in communication with intake duct 41 and oil thereinis displaced by downward movement of piston 29 when the passage 43communicates with discharge duct 42. j

The stroke of piston 29 is adjusted by means of a sleeve 27 to which acable pulley 28is secured. Sleeve 27 is journaled around housing 30 ofthe pump 3 in the region enclosing piston 29. As best seen in FIG. 7,sleeve 27 has a slot 31 inclined with respect to its longitudinal axisand extending around a portion of its circumference. A pin 32 fixedlysecured in housing 30 and extending into slot 31 provides a follower forthe camming surfaces of the walls of slot 31. A torsion spring 33coaxial with sleeve 27 is connected to the cable pulley 28 at one endand at the other end to a cover 34 fixed on the pump housing 30. A liftplate 35 abuts the upper end of sleeve 27 and pulley 28 and is fixedagainst axial motion relative to piston 29 by nut 26.

Displacement of cable 12 to the right as viewed in FIGS. 5 and 6 altersthe stroke of the piston 29 by raising the piston so that its strokeimparted by the lift of cam 46 is reduced. This reduces the output ofthe pump for each revolution of the crankshaft of engine 1. The maximumrotary motion of sleeve 27 is limited by the length of slot 31 and therange stroke adjustment depends upon the difference in position alongthe axis of the piston of the extremes of the slot. As the slot wallsengaging pin 32 fall along the axis of the sleeve, the fixed pin causesthe sleeve and pulley 28 to be lifted with respect to the housing 30.The engagement of sleeve 27 with plate 35 raises the piston 29 relativeto housing 30 so that the falling face of cam 46 does not follow stud 48over the entire arc of travel of that face and the intake stroke of thepiston 29 is reduced. The degree of reduction of stroke is a function ofthe amount of rotary motion of cable pulley 28 for a given slotinclination. The resultant reduction of the piston stroke diminishes thequantity of oil displaced to the discharge duct 42 for each revolutionof the engine crankshaft.

Release of cable 12 toward the left as viewed in FIGS. 5 and 6 permitstorsion spring 33 to move the sleeve 27 with cable pulley 28 clockwiseso that fixed pin 32 moves relative to slot 31 to the right as viewed inFIG. 7. This permits the lifting plate 35 to be moved toward housing 30under the influence of compression spring 49 so that cam 46 rests onstud 48 during a greater portion of the revolution of piston 29 toincrease the stroke of the piston. At the limit, when pin 32 is at theright-hand end of slot 31, the cam 46 follows stud 48 throughout eachpiston rotation and a maximum stroke results. A failure of cable 12 setsthe pump at maximum.

FIG. 8 shows a conventional carburetor 2 having a piston 38 biases bycompression spring 37 toward the closed position. The illustrated closedposition represents the no-load setting for the engine 1. Tensionapplied by Bowden cable 9 lifts piston 38 to increase the load settingfor the engine. A failure of cable 9 closes duct 39 by advancing piston38. The carburetor needle valve is designated as 40.

The invention as described lends itself to modification and variationsas the actuating means and linkages, accordingly it is to be understoodthat the above description is to be read as illustrative and not in alimiting sense.

I claim:

1. An internal combustion engine comprising, a crankshaft, a throttle, alubricant supply means having an output per crankshaft revolution whichis adjustable, adjustment means for said lubricant supply means toadjust said output, a control linkage to said throttle and saidadjustment means arranged to coordinate said throttle and adjustmentmeans setting whereby an increased engine output setting results in anincreased output per crankshaft revolution setting for said lubricantsupply, and biasing means coupled to said adjustment means for drivingsaid adjustable lubricant supply means toward a maximum output percrankshaft revolution setting when said adjustment means isunconstrained by said control linkage.

2. A combination according to claim ll wherein said lubricant supplymeans is an adjustable output pump.

3. A combination according to claim 1 wherein said control linkagecomprises a first cable to said throttle, a spring biasing said firstcable to drive said throttle toward the position of no load setting, asecond cable to said adjustment means, said biasing means comprising aspring biasing said second cable, and a common operating device coupledto said first and second cables and adapted to move said cables inopposite sense.

4. A combination according to claim 3 wherein said first and secondcables are Bowden cables.

5. A combination according to claim 3 wherein said common operatingdevice is a two armed lever with said first cable connected to a firstarm thereof and said second cable connected to a second arm thereof.

6. A combination according to claim 3 wherein said common operatingdevice is a slider, and a guide for said slider to adapt said slider forfor reciprocating motion.

7. A combination according to claim 3 wherein said common operatingdevice is a rotatable element and said cables are attached to saidrotating element and each have a portion extending around the axis ofrotation of said rotating element from opposite sides thereof.

8. A combination according to claim 2 wherein said biasing is a torsionspring tending to bias said adjustment means to urge said pump towardthe maximum supply setting.

9. A combination according to claim 3 including a carburetor for saidengine and wherein said first spring is a compression spring functioningas a control element of a throttle on said carburetor.

1. An internal combustion engine comprising, a crankshaft, a throttle, alubricant supply means having an output per crankshaft revolution whichis adjustable, adjustment means for said lubricant supply means toadjust said output, a control linkage to said throttle and saidadjustment means arranged to coordinate said throttle and adjustmentmeans setting whereby an increased engine output setting results in anincreased output per crankshaft revolution setting for said lubricantsupply, and biasing means coupled to said adjustment means for drivingsaid adjustable lubricant supply means toward a maximum output percrankshaft revolution setting when said adjustment means isunconstrained by said control linkage.
 2. A combination according toclaim 1 wherein said lubricant supply means is an adjustable outputpump.
 3. A combination according to claim 1 wherein said control linkagecomprises a first cable to said throttle, a spring biasing said firstcable to drive said throttle toward the position of no load setting, asecond cable to said adjustment means, said biasing means comprising aspring biasing said second cable, and a common operating device coupledto said first and second cables and adapted to move said cables inopposite sense.
 4. A combination according to claim 3 wherein said firstand second cables are Bowden cables.
 5. A combination according to claim3 wherein said common operating device is a two armed lever with saidfirst cable connected to a first arm thereof and said second cableconnected to a second arm thereof.
 6. A combination according to claim 3wherein said common operating device is a slider, and a guide for saidslider to adapt said slider for for reciprocating motion.
 7. Acombination according to claim 3 wherein said common operating device isa rotatable element and said cables are attached to said rotatingelement and each have a portion extending around the axis of rotation ofsaid rotating element from opposite sides thereof.
 8. A combinationaccording to claim 2 wherein said biasing is a torsion spring tending tobias said adjustment means to urge said pump toward the maximum supplysetting.
 9. A combination according to claim 3 including a carburetorfor said engine and wherein said first spring is a compression springfunctioning as a control element of a throttle on said carburetor.